diff --git a/fuzzers/050-pip-seed/Makefile b/fuzzers/050-pip-seed/Makefile
index bce3bb1a..2dc96edd 100644
--- a/fuzzers/050-pip-seed/Makefile
+++ b/fuzzers/050-pip-seed/Makefile
@@ -9,7 +9,7 @@ N ?= 48
 SEGMATCH_FLAGS=-m 15 -M 45
 endif
 
-CHECK_ARGS="--max-iters 12 --min-progress 50"
+CHECK_ARGS=--max-iters 12 --min-progress 50
 
 include ../pip_loop.mk
 
diff --git a/fuzzers/pip_loop.mk b/fuzzers/pip_loop.mk
index ea8e6423..bd9d8b82 100644
--- a/fuzzers/pip_loop.mk
+++ b/fuzzers/pip_loop.mk
@@ -20,7 +20,7 @@ SPECIMENS_DEPS ?=
 
 # See int_loop_check.py
 # rempips took 35 iters once, so set 50 as a good start point
-CHECK_ARGS := --zero-entries --timeout-iters 50
+CHECK_ARGS ?= --zero-entries --timeout-iters 50
 SPECIMENS := $(addprefix build/$(ITER)/specimen_,$(shell seq -f '%03.0f' $(N)))
 SPECIMENS_OK := $(addsuffix /OK,$(SPECIMENS))
 # Individual fuzzer directory, such as ~/prjxray/fuzzers/010-lutinit